Enhanced restart of a core dumping application

ABSTRACT

A method for enhanced restart of a core dumping application is provided. The method includes stopping a plurality of threads in an address space, except for the thread performing the core dump. Computational segments are remapped to client segments. Each open file descriptor in the address space is closed. The application is terminated and the client segments are flushed to external storage.

BACKGROUND

This disclosure relates generally to computer systems, and moreparticularly to faster core dump completion, thus allowing fasterapplication restarts.

A core dump includes the program state data and contents of computermemory that a computer program is using at a given point in time. A coredump may be initiated at any time the application program is running,but more typically the core dump occurs when the application programabnormally terminates due to a severe error condition. The program statedata includes: computer system control structures, such as page tables;status flags; processor registers; program instruction counter; andstack pointer. While the core dump is being created and written tostorage, the application program's resources, such as shared memorysegments, and inter-process communication (IPC) sockets, remain in useuntil the core dump process completes. Therefore, restarting theapplication program and its processes is delayed for the duration of thecore dump process because the new instance of the application programneeds the resources currently in use. Especially when the applicationprogram consumes large amount of system resources, collecting the coredump data becomes time consuming in view of increasingly strict systemavailability requirements. An application program may have a customizedfile format for saving state data for later problem determination.However, to be effective, the file would have to be well designed tocapture the appropriate data for any given problem, yet be small enoughto enable quicker restart of the application program. Additionally,modifications to the application program would result in re-design ofthe customized file, leading to costly investment in maintenanceresources to be effective. Consequently, system administrators may beencouraged to either prematurely abort core dumps, or to collect onlypartial core dumps, rather than extend the duration of the applicationprogram outage.

SUMMARY

According to one embodiment, a method for enhanced restart of a coredumping application is provided. The method includes: stopping aplurality of threads in an address space; continuing a thread, whereinthe thread performs a core dump; remapping a computational segment to aclient segment; closing each open file descriptor in the address space;terminating the core dumping application; and flushing the clientsegment to an external storage.

According to another embodiment, a computer program product for enhancedrestart of a core dumping application is provided. The computer programproduct includes a computer readable storage medium readable by aprocessing circuit and storing instructions for execution by theprocessing circuit for performing a method is provided. The methodincludes: stopping a plurality of threads in an address space;continuing a thread, wherein the thread performs a core dump; remappinga computational segment to a client segment; closing each open filedescriptor in the address space; terminating the core dumpingapplication; and flushing the client segment to an external storage.

According to another embodiment, a computer system for enhanced restartof a core dumping application is provided. The computer system includesa memory, a processing unit communicatively coupled to the memory, and amanagement module communicatively coupled to the memory and processingunit, whereby the management module is configured to perform the stepsof a method is provided. The method includes: stopping a plurality ofthreads in an address space; continuing a thread, wherein the threadperforms a core dump; remapping a computational segment to a clientsegment; closing each open file descriptor in the address space;terminating the core dumping application; and flushing the clientsegment to an external storage.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a more complete understanding of this disclosure, reference is nowmade to the following brief description, taken in conjunction with theaccompanying drawings and detailed description, wherein like referencenumerals represent like parts.

FIG. 1 illustrates an exemplary computing node operable for variousembodiments of the disclosure.

FIG. 2 illustrates computer memory regions of an exemplary address spacefor a computer process.

FIG. 3 illustrates a portion of exemplary control structures formanaging computer memory regions.

FIG. 4 is an operational flowchart illustrating an algorithm forenhanced restart of a core dumping application, according to variousembodiments of the disclosure.

FIG. 5 is a schematic block diagram of hardware and software of thecomputer environment according to an embodiment of the processes of FIG.4.

DETAILED DESCRIPTION

Although an illustrative implementation of one or more embodiments isprovided below, the disclosed systems and/or methods may be implementedusing any number of techniques. This disclosure should in no way belimited to the illustrative implementations, drawings, and techniquesillustrated below, including the exemplary designs and implementationsillustrated and described herein, but may be modified within the scopeof the appended claims along with their full scope of equivalents.

The present disclosure relates generally to the field of computersystems, and more particularly to an enhanced restart of a core dumpingapplication. In current operation, an application may not restart untilthe core dump completes, since the restarted application requires theresources held by the core dumping application, and pages are copiedfrom the address space to a temporary memory area prior to writing thecore dump to the core file. The following described exemplaryembodiments provide a system, method and program product to reduce thetime required to collect diagnostic information and restart a failedapplication program. The technical effects and benefits include theability to reduce the time that an application is unavailable to thebusiness enterprise, and the conservation of memory and computer systemresources by eliminating the intermediate copy to temporary memory.

As will be appreciated by one skilled in the art, aspects of the presentdisclosure may be embodied as a system, method or computer programproduct. Accordingly, aspects of the present disclosure may take theform of an entirely hardware embodiment, an entirely software embodiment(including firmware, resident software, micro-code, etc.) or anembodiment combining software and hardware aspects that may allgenerally be referred to herein as a “circuit”, “module”, or “system”.Furthermore, aspects of the present invention may take the form of acomputer program product embodied in one or more computer readablemedium(s) having computer readable program code embodied thereon.

Aspects of the present disclosure are described below with reference toflowchart illustrations and/or block diagrams of methods, apparatus,(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer program instructions.

Turning now to FIG. 1, a block diagram of an exemplary computer system(server) 12 operable for various embodiments of the disclosure ispresented. As shown, the server 12 is only one example of a suitablecomputer for enhanced restart of a core dumping application, and is notintended to suggest any limitation as to the scope of use orfunctionality of embodiments of the disclosure described herein.

The server 12 is operational in numerous other computing systemenvironments or configurations. For example, the server 12 may be astandalone machine, a virtual partition on physical host, a clusteredserver environment, or a distributed cloud computing environment thatinclude any of the above systems or devices, and the like. Whenpracticed in a distributed cloud computing environment, tasks may beperformed by both local and remote servers 12 that are linked togetherand communicate through a communications network, such as the network99.

The server 12 may be described in the context of executableinstructions, such as a program, or more specifically, an operatingsystem (OS) 40 that is an aggregate of program modules 42 being executedby the processing unit 16 to control the operation of the server 12.Program modules 42 perform particular tasks of the OS 40, such asprocess management; memory management; and device management. Theprogram modules 42 may be implemented as routines, programs, objects,components, logic, or data structures, for example. The program modules42 performing the particular tasks may be grouped by function, accordingto the server 12 component that the program modules 42 control. At leasta portion of the program modules 42 may be specialized to execute thealgorithms of FIG. 4.

In a distributed computing environment, such as a cloud computingenvironment, each participating server 12 may be under the control of anOS 40 residing on each local and remote server 12, respectively. In avirtual machine, also referred to as a virtual server, each instance ofthe virtual machine is an emulation of a physical computer. A physicalcomputer may host multiple virtual machine instances, each sharing thehardware resources of the physical computer, and each emulating aphysical computer. Each of the virtual machine instances is under thecontrol of an OS 40.

As shown in FIG. 1, the components of the server 12 may include, but arenot limited to, one or more processors or processing units 16, a systemmemory 28, and a bus 18 that couples various system components, such asthe system memory 28, to processor 16.

System memory 28 can include computer system readable media in the formof volatile memory, such as random access memory (RAM) 30 and/or cachememory 32. The server 12 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia.

By way of example only, a storage system 34 can be provided as one ormore devices for reading from and writing to a non-removable,non-volatile magnetic media, such as a hard disk drive (HDD) or anoptical disk drive such as a CD-ROM, DVD-ROM. Each device of the storagesystem 34 can be connected to bus 18 by one or more data mediainterfaces. The program modules 42, the OS 40, and one or moreapplication programs may be stored on the storage system 34 andsubsequently loaded into memory 28 for execution, as needed.

The server 12 may also communicate with one or more external devices 14such as a keyboard, a pointing device, a display 24, etc.; one or moredevices that enable a user to interact with the server 12; and/or anydevices (e.g., network card, modem, etc.) that enable the server 12 tocommunicate with one or more other computing devices. Such communicationcan occur via I/O interfaces 22. Still, the server 12 can communicatewith one or more networks such as a local area network (LAN), a generalwide area network (WAN), and/or a public network (e.g., the Internet)via a network adapter 20. As depicted, the network adapter 20communicates with the other components of the server 12 via bus 18.External storage adapter 26 connects the server 12 with external storagesubsystems, such as a storage area network (SAN) 15 or RAID array.Exemplary external storage adapters 26 include, but are not limited to,a host bus adapter (HBA), host channel adapter (HCA), SCSI, and iSCSI,depending upon the architectural implementation. The external storageadapter 26 communicates with the processing unit 16 and memory 28 of theserver 12 over bus 18.

It should be understood that although not shown, other hardware and/orsoftware components could be used in conjunction with the server 12.Examples include, but are not limited to: microcode, device drivers,redundant processing units, external disk drive arrays, RAID systems,tape drives, and data archival storage systems, etc.

Referring now to FIG. 2, computer memory regions (not to scale) of anexemplary process address space 200 are illustrated. In someimplementations, the address space of the kernel of the OS 40 (FIG. 1)may differ in content and structure from a process address space.Therefore as used herein, an address space refers the address space of aprocess. The address space, also referred to as a context, representsthe range of addressable locations that are allocated to a process. In alinear, or flat, memory model, the memory allocated to an address spaceappears to be a contiguous range of addresses. However, in a segmentedmemory model, an address space 200 is allocated in terms of segments,for example, of 256 megabytes (MB) each. A reference to an address in asegmented address space includes invoking server 12 hardware and OS 40(both of FIG. 1) components to identify the segment containing the pagereference and subsequently translating the virtualized address from thesegment to a real address. The segmented memory model allows a processto appear to have full access to all of server 12 physical RAM 30 (bothof FIG. 1), and also appear to reference more RAM 30 (FIG. 1) than isphysically present. The concept of translating virtualized addresses toreal addresses is both well-known in the art and implementationdependent. Therefore, address translation, as such, will not bediscussed with reference to the present disclosure, since anyimplementation may be used. While the present disclosure is described asan exemplary segmented memory implementation, the present disclosure maybe implemented in a linear, or other, memory model, according to thearchitecture of the selected memory model.

A layout of address regions in an address space implementation may bevendor or platform specific. For example, the address space 200 may besimilar to a representation of a 64-bit address space in the Linux® orAIX® OS 40 (FIG. 1). However, each may differ from a Windows® addressspace 200 implementation, for example. Linux is the registered trademarkof Linus Torvalds in the United States, other countries, or both. AIX isthe registered trademark of International Business Machines Corporationin the United States, other countries, or both. Microsoft, Windows, andthe Windows logo are trademarks of Microsoft Corporation in the UnitedStates, other countries, or both.

The kernel segment 205 occupies the top of the address space 200. Thisrange of addresses is not available to the process. The programenvironment 210 segment includes, among other things, the name of theprocess being executed and arguments that are passed into the process atstart of execution. The user memory attachment segments 215 areavailable for the process to add a shared memory segment to the addressspace 200. The attached segment may be used to map a file from externalstorage into process memory, or for communicating between two or moreprocesses, also referred to as inter process communication (IPC). Theprogram text 220 segment includes the executable code that comes fromthe program running in the address space 200. The program data 225segment includes both initialized and uninitialized global variablesthat the process is using. User heap is an area of pre-reserved memorythat the process explicitly allocates and frees to store data in someamount that may be unknown until the process is executing. The sharedlibrary text and data 235 segment represents the area in the addressspace 200 into which the OS 40 (FIG. 1) maps a reference to a sharedlibrary. However, the shared library may not be physically included inthe address space 200. A shared library may contain common functions,such as for printing or mathematical calculations, that are used byseveral processes. Through other OS 40 (FIG. 1) components, such as thelinker and loader, the process may refer to variables and invokefunctions that are defined and located in the shared library. Mapping amemory reference to the shared library rather than copying the libraryinto the address space 200 not only saves memory resources, but alsoensures that the processes are using a uniformly consistent copy of thelibrary functions. The user thread stack 240 segment includes the returnaddresses, parameters, and local variables of the function beingexecuted.

In some implementations, the pages that the OS 40 (FIG. 1) identifies asbelonging to the kernel segment 205, the program data 225 segment, theshared library text and data 235 segment, and the user thread stack 240segment may be referred to as containing working storage pages. Theseare pages that contain volatile data that is not preserved across areboot, such as by being backed by persistent file system storage.Working storage pages may also be referred to as computational pages. Inother implementations, working storage pages may be referred to asanonymous memory. In an embodiment, a client segment that containsclient pages may be implemented. Client pages may be referred to asthose pages that contain cached data for files being read and writtento.

In FIG. 3, 300 illustrates a portion of exemplary control structuresthat may be implemented for managing computer memory regions in asegmented memory model. As shown in 300, the segment control blocks(SCB) 315 may be arranged in an array that is indexed by an index 310.Each SCB 315 may include: an identification of the type of segment; acount of pages in the segment, for example, allocated pages and pinnedpages; and a pointer to the descriptors 320. Each SCB may containmultiple descriptors 320. A descriptor 320 may be a structure foridentifying the address and location, for example in memory or on apaging device, of the page being described. A descriptor 320 mayadditionally include a pointer ptr 325 to a structure that may be usedto translate a virtualized address to a real address. In thisimplementation, each SCB 315 indicates the segment type, such as workingstorage or client storage. The control structures of FIG. 3 arepresented by example, not by limitation, as those skilled in the art maywell realize.

Referring now to FIG. 4, an algorithm for enhanced restart of a coredumping application, according to various embodiments of the disclosure,is illustrated. A core dump may be initiated manually, or as a result ofa program abnormally terminating due to a severe error condition. Uponinitiation of a core dump, at 400 the OS 40 (FIG. 1) stops threads thatare still executing in the address space 200 (FIG. 2), except for thethread that is performing the core dump.

At 410, the OS 40 (FIG. 1) writes header information to the core filefor subsequent use by a diagnostic utility in interpreting the formatand contents of the file. Among other information, the header mayinclude: an indicator of the file format, such as executable andlinkable format (ELF); an indicator of the target instruction setarchitecture; and at least one pointer to the data sections in the corefile.

At 415, the OS 40 (FIG. 1) writes to the core file the state of theprocess threads. In computing, a process may include one or morethreads. A thread may represent an independent stream of programinstructions that the OS 40 (FIG. 1) may schedule to run simultaneouslyand independently of other threads in the process. Being an independentstream of program instructions, a thread may maintain structures thatare similar to those of the main process, including: a stack pointer;registers; scheduling properties, such as priority; signals; andthread-specific data.

At 420, the OS 40 (FIG. 1) writes to the core file the descriptor datafor each open file in the address space 200 (FIG. 2). A file descriptorrepresents an index into an array of open files in a process or thread.Operations such as to read, write, open, and close a file use the filedescriptor to locate the target of the I/O operation. The filedescriptor, according to the vendor-specific implementation, may pointto at least one structure that identifies: the file name and location;and the I/O operation and status. A file may include: directories andpersistent locations containing data, for example on disk drives;standard input, for example through a keyboard; a pipe, which may beused for IPC between a parent and child process; and a socket, which maybe used for IPC across a computer network.

At 425, the OS 40 (FIG. 1) writes the load table information for theprocess to the core file. As described previously with reference to FIG.2, a shared library is one that contains functions or procedures thatare used by multiple processes, but that is only included in the addressspace 200 (FIG. 2) by a mapped memory reference. Since an address space200 (FIG. 2) may include more than one shared library, at 425 the OS 40(FIG. 1) writes the location where the shared library is mapped in theaddress space. Addresses are resolved for symbols and functions used bythe process but defined in the shared library.

At 430, the OS 40 (FIG. 1) maps computational pages as client pages. Asdescribed previously with reference to FIGS. 2 and 3, working storagepages may be referred to as computational pages or non-persistent pagessince they are not backed by persistent file system storage, and clientpages contain cached data for file I/O. The SCB 315 (FIG. 3)participates with components of the server 12 hardware and the OS 40(both of FIG. 1) to identify and locate pages associated with theaddress space (FIG. 2). The OS 40 (FIG. 1) may obtain a client segmentto receive the descriptors 320 (FIG. 3) from a working storage segment.Upon locating a segment containing working storage type pages, the OS 40(FIG. 1) may remap, i.e., copy the descriptors 320 (FIG. 3) from theworking storage segment into the client segment. Since a segment may beonly partially allocated, only those descriptors 320 (FIG. 3) thatcorrespond to an allocated page are copied. The components of the server12 hardware and the OS 40 (both of FIG. 1) may cooperate to locate thepage, for example through the ptr 325 (FIG. 3) and make the pageavailable for writing to the core file. For example, a page that ispaged out may be brought into memory from the external paging device.

At 435, the OS 40 (FIG. 1) adjusts the page type counts. The SCB 315(FIG. 3) may include a count of how many pages are present in thesegment. The page count in the working storage segment is decrement foreach descriptor 320 (FIG. 3) that is removed, and the page count in theclient segment is incremented for each corresponding descriptor 320(FIG. 3) that is added to the client segment.

At 440, the open file descriptors and IPC descriptors that areassociated with the address space 200 (FIG. 2) may be closed, and sharedmemory segments that are attached to the address space 200 (FIG. 2) maybe released. When the client segment is written to the core file,according to OS 40 (FIG. 1) protocols, the application program may beterminated and restarted.

Referring now to FIG. 5, computing device 500 may include respectivesets of internal components 800 and external components 900 thattogether may provide an environment for a software application. Each ofthe sets of internal components 800 includes one or more processors 820;one or more computer-readable RAMs 822; one or more computer-readableROMs 824 on one or more buses 826; one or more operating systems 828executing the method of FIG. 4; and one or more computer-readabletangible storage devices 830. The one or more operating systems 828(including the additional data collection facility) are stored on one ormore of the respective computer-readable tangible storage devices 830for execution by one or more of the respective processors 820 via one ormore of the respective RAMs 822 (which typically include cache memory).In the embodiment illustrated in FIG. 5, each of the computer-readabletangible storage devices 830 is a magnetic disk storage device of aninternal hard drive. Alternatively, each of the computer-readabletangible storage devices 830 is a semiconductor storage device such asROM 824, EPROM, flash memory or any other computer-readable tangiblestorage device that can store a computer program and digitalinformation.

Each set of internal components 800 also includes a R/W drive orinterface 832 to read from and write to one or more computer-readabletangible storage devices 936 such as a CD-ROM, DVD, SSD, memory stick,magnetic tape, magnetic disk, optical disk or semiconductor storagedevice.

Each set of internal components 800 may also include network adapters(or switch port cards) or interfaces 836 such as a TCP/IP adapter cards,wireless WI-FI interface cards, or 3G or 4G wireless interface cards orother wired or wireless communication links. The operating system 828that is associated with computing device 500, can be downloaded tocomputing device 500 from an external computer (e.g., server) via anetwork (for example, the Internet, a local area network, or other widearea network) and respective network adapters or interfaces 836. Fromthe network adapters (or switch port adapters) or interfaces 836 andoperating system 828 associated with computing device 500 are loadedinto the respective hard drive 830 and network adapter 836. The networkmay comprise copper wires, optical fibers, wireless transmission,routers, firewalls, switches, gateway computers and/or edge servers.

Each of the sets of external components 900 can include a computerdisplay monitor 920, a keyboard 930, and a computer mouse 934. Externalcomponents 900 can also include touch screens, virtual keyboards, touchpads, pointing devices, and other human interface devices. Each of thesets of internal components 800 also includes device drivers 840 tointerface to computer display monitor 920, keyboard 930 and computermouse 934. The device drivers 840, R/W drive or interface 832 andnetwork adapter or interface 836 comprise hardware and software (storedin storage device 830 and/or ROM 824).

Various embodiments of the invention may be implemented in a dataprocessing system suitable for storing and/or executing program codethat includes at least one processor coupled directly or indirectly tomemory elements through a system bus. The memory elements include, forinstance, local memory employed during actual execution of the programcode, bulk storage, and cache memory which provide temporary storage ofat least some program code in order to reduce the number of times codemust be retrieved from bulk storage during execution.

Input/Output or I/O devices (including, but not limited to, keyboards,displays, pointing devices, DASD, tape, CDs, DVDs, thumb drives andother memory media, etc.) can be coupled to the system either directlyor through intervening I/O controllers. Network adapters may also becoupled to the system to enable the data processing system to becomecoupled to other data processing systems or remote printers or storagedevices through intervening private or public networks. Modems, cablemodems, and Ethernet cards are just a few of the available types ofnetwork adapters.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Although preferred embodiments have been depicted and described indetail herein, it will be apparent to those skilled in the relevant artthat various modifications, additions, substitutions and the like can bemade without departing from the spirit of the disclosure, and these are,therefore, considered to be within the scope of the disclosure, asdefined in the following claims.

What is claimed is:
 1. A computer system for enhanced restart of a coredumping application, the computer system comprising: a computer readablememory; a processing unit communicatively coupled to the computerreadable memory; a computer readable storage medium; and programinstructions stored on the computer readable storage medium forexecution by the processing unit via the computer readable memory, theprogram instructions comprising: program instructions to stop aplurality of threads in an address space; program instructions tocontinue a thread, wherein the continued thread performs a core dump;program instructions to remap a computational segment to a clientsegment, wherein the remapping comprises: program instructions to obtainthe client segment, wherein the client segment includes a plurality ofclient pages, and wherein the client pages comprise cached file data;program instructions to copy a plurality of segment descriptorsassociated with a plurality of computational pages from thecomputational segment to the client segment; program instructions todecrement a first count, wherein the first count corresponds to a numberof computational pages identified by the plurality of segmentdescriptors copied from the computational segment; and programinstructions to increment a second count, wherein the second countcorresponds to the number of computational pages identified by theplurality of segment descriptors copied to the client segment; programinstructions to close each open file descriptor in the address space;program instructions to terminate the core dumping application; andprogram instructions to flush the client segment to an external storage.